Bromothymol blue and Bromocresol purple as efficient reagents for the development and validation of visible spectrophotometric assay methods for Felodipine

Abstract

Bromothymol blue (BTB) and Bromocresol purple (BCP) are introduced as reagents that can help in developing and validating two simple and low cost visible spectrophotometric methods for the determination of Felodipine drug in pure form as well as in formulations. The new methods are based on attraction between positive charge on the nitrogen of drug molecule and the negative charge of BTB as well as BCP to produce coloured complexes. The coloured complexes exhibited absorption maxima at 420 nm and 415 nm respectively for BTB and BCP. It was found that the results obtained by the proposed methods and the labeled amounts are in good agreement. The relative standard deviations of the proposed methods are found to be 1.557% and 1.807%. Based on all the results, it is concluded that the proposed methods offer low cost, simple, sensitive and rapid process of determining and validating the selected drug using visible spectrophotometry.